Of the seven existing classes of serotonin receptors, the 5-HT7 receptors (5-HT7Rs) are the most recently discovered. Abundance of 5-HT7 in the central nervous system is suggestive of the receptor’s role in several physiological and pathophysiological functions. Existing research has afforded a number of compounds exhibiting specific affinity to the receptor. These selective ligands can provide structural information about the receptor and can serve as the foundation for pharmacological profiling . This thesis describes the synthesis of substituted pyrimidines and pyridines for affinity to the 5-HT7 receptor. Organometallic species are the cornerstone for sev-eral of the synthetic pathways.